Compounds of leuco vat dyes with aralkyl compounds and process of making same.



UNITED STATES PATENT OFFICE.

KARL REINKING AND ARMANI) JULIUS S'lIIEGELMANN, 'OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNORE; T0 BADISCHE ANILIN & SODA FABRIK, 01 L171?-WIGSHAFEN-ON-THE-RHINE, GERMANY, A CQRPOBATION.

COMPOUNDS OF LEUCO VAT DYES WITH ARALKYL COMPOUNDS AND PROCESS OF MAKINGSAME.

No Drawing.

Specification of Letters Intent.

Application filed September 28 1910. Serialito. 584,299.

Patented Aug. 11, 1914.

To all whom it may concern:

Be it known that we, KARL REINK-ING and ARMAND JULIUS STIEGELM'ANN',doctors of philosophy and chemists, sub ects respectively, of the PrinceRegent of Brunswick and of the Emperor of Germany,

of which the tel-lowing is a specification Our invention relates to theproduction of i .a new class of compounds and to a rocess of producingthese compounds. We ave .dis-

covered that the leuco compounds of vat under which term we incoloringmatters,

elude indigo, halogen-indigo, and other dyes of the ind go class, andalso dyestuffs of the t'h'ioindigo class, indanthrene dyes, the 'vartunder the name of algol dyes, suld. es sol y can combine with aralkylresidues to that they are comparatively stable in the air,

that is, they are not liable to be oxidized into the correspondingcoloring matter, thus difffering from the leuco compounds themselves.Under the term aata'l'kyl residue we-1-n-' clude the mixed residues,such as benzyl,

whichcontain both an aromatic and an ali-' phatic rad icle, the .saidaliphatic radic'le containing afree valency.

The aralky'l compounds which can be used as the source of the aralky lresidues according to this invention possess a residue with aconstitution corresponding to the general formula in which R representshydrogen, halogen,

sulfonic acid and benzyl-.chlorid-para+sulfochlorid, benzal chlorid, andas particularly residing at Ludwigshafen-on-the-Rhine, Germany, haveinvented new and useful Improvements in: Compounds of Leuco Vat Dyeswith Aral-kyl Compounds and Processes of Making Same,

useful the organic ammonium compounds which contain ,an aral'k lresidue, such for instance as dimethyi-phenyl-benzyl-ammomum chlorid andthose ammonium compounds which are obtainable by combining benzylchloridwith dialkyl meta-aminophenol or with tetra-methyl-diamino-diphenyl-methane, or with leuco malachite green or with the carbinol baseof malachite green, .or with leuco crystal violent. The sulfoni'u-m comounds which are obtainable by combining enzyl haloid with ,a dialkylsulfid, such as dimethy'l sulfid, ,are also capable of use according toour invention; or We can employ substituted benzyl .haloid, .such forinstance as para-chlot-benzyl chlorid, omega-chlorara-xylol,omega-chlorbeta1methyl-naph alene, and omega-chlonbetamethyl-anthraquinone, and we can employ these compounds either assuch or in a state of combination such that the aralkyl residue isavailable for combining with the leuco vat coloring matter, for instancethe said substituted benzyl haloids may be combined with a tertiaryam'in, such as dimethyl-anilin, or with a dialkyl sulfid, such asdimethyl sulfid. In some cases it may be advisable to employ a mixtureof a benzyl halo'id admixed with a tertiary amin or the like without itsbeing necessary previously to combine the tertiary amin with the benzylha'loid. Aralkyl compounds which do not give up an ara-lkyl residue toenable it to combine with a leuco compound of a vat col-- or'ing matter,for instance benzyl-anilin-sulfonic acid and dibenz-yl oxid, are notcapable of use according to our invention. As aforesaid, our newcompounds are comparatively stable in the presence of air andconsequently, when avat coloring matter is treated on the fiber with areducing agent in the presence of an ara'lkyl compound as aforesaid, oneof our new stable compounds, containing the leuco vat coloring matterand the aralkyl residue, is formed and remains-as such on the fiber.Since this compound is stable in the air, the material does those caseswhere no aralkyl com-pound is not need to be treated with "such care asthe discharged portions on the fiber, when the goods are taken out ofthe steaming apparatus, are very sensitive and unless very goodapparatus be employed and very great care be taken, pure dischargeeffects are not obtained. lVhen, however, an aralkyl compound of thetype described is added to the discharging paste, discharge effects canbe obtained which are not sensitive to the air and consequently remainpure. Our invention is therefore of great benefit to the trade becauseit enables large quantities of material to be treated with thedischarging paste and then steamed without its being necessaryimmediately to remove, by washing or otherwise, the resulting productsof the reduction of vat coloring matter.

As a rule, when the aralkyl residue contains a group capable of forminga salt, such for instance as a sulfonic acid group or a carboXylic acidgroup or a hydroxyl group, the compounds which it forms with the leucocoloring matter are easily soluble in an alkaline bath, and consequentlythey can be readily washed away from the fiber and White dischargeeffects can thus be pro duced on fiber which has been dyed with the vatcoloring matter. On the other hand, when the aralkyl compound employedcon-. tains no such group capable of forming a salt attached directly tothe aralkyl residued the compounds formed containing the ai'alkylresidue and the leuco compound of the coloring matter are sometimesinsoluble inacid or alkali and remain fixed on the fiber.; Thus, forinstance, if thioindigo be dis-. charged, a slightly colored compoundis. formed which can easily be washed away' leaving pure white effects.On the other hand, if material dyed with indigo be discharged whileemploying an aralkyl compound, such as dimethyl-phenyl-benzyl-ammoniumchlorid a compound of an intensely yellow color is formed, and, as thisis stable in the air and also fairly stable against the action ofsolvents, yellow discharge elfects can thus be obtained. -These yelloweffects can be shaded oil and at the same'time be made more stableby-adding to the dis-- charging paste a metalliccompound, such. as anoxid, or hydroxid, or a salt. For instance, if zinc oxid be added, abrilliant orange is obtained capable of withstanding the action ofboiling alkali, whereas if magnesia be used, a sulfur yellow isproduced, while alumina gives rise to a cream color, and iron oxid to abrownish olive color. The homologues and substitution products of indigobehave in a similar manner. The

indigoid coloring matter obtainable from dibrom-isatin chlorid andalphaanthrol gives riseto a red compound. If an aralkyl residuecontaining a sulfonic acid group, such for instance as a sulfonic acidderivative of dimenthyl-phenyl-benzyl-ammonium chlorid containing thesulfonic acid group in the benzyl residue, be added to the dischargingpaste, pure white effects can be produced on material which has beendyed with indigo. In this case yellowish compounds are at firstproduced, but they can be entirely removed from the fiber by treatmentwith a hot alkaline bath such as is generally employed after sodiumformaldehyde sulfoxylate has been used for discharging vat coloringmatters. Owing to the extreme'solubility in alkali of the yellowishintermediate products produced when discharging indigo dyeings with theaid of a sulfonic acid of an organic ammonium compound, the dischargingprocess as a whole is simplified, because the goods do not require to betreated for so long a time in the hot alkaline bath and this bath cancontain less alkali and can also be employed at a lower temperature. Inthis case also, the addition of a metallic oxid is advantageous, zincoxid being particularly-useful for this purpose.

In carrying out the process of this invention, the vat coloring mattercan be reduced to its leuco compound by means of any suitable reagentforinstance, formalydehyde sulfoxylate, formaldehyde hydrosulfite, andhydrosulfite, are very suitable for the purpose, but other reducing, ordischarging, agent, can be employed, such for instance as a suitablecarbohydrate, or stannous oxid, and in some cases even the reducingaction exercised by the usual thickening agents in the presence ofcaustic alkali is sufiicient to produce the result desired. The samecompounds are produced whether the combination of the aralkyl residuewith the leuco coloring matter takes place in the presence of the fiberor otherwise.

During the discharge, other coloring inatters may be present for thepurpose of prcr ducing various colored discharge effects and of coursewhen preparing the discharge .pastes according to this invention, othersuitable ingredients, such for instance as alkalis, oil of turpentineand glycerin, which enhances the printing properties of the paste, or acatalytic agent which assists in the reduction, such, for instance, asanthraquinone, can be addcdf As aforesaid, those compounds in which thearalkyl residue contains no group capable of forming a salt, such as asulfonic acid group or a carboxylic acid group of a hydroxyl group, tendgenerally to yield in:

soluble compounds with the leuco vat coloring matters, in particularwith indigo white, while those in which the aralkylresidue contains sucha group capable of forming a salt, tend to yield soluble compounds withthe leuco vat coloring matter. Thus for instance thedimethyl-phcnyl-benzyl-ammonium chl'orid sulfonic acid in which thesulfonic acid is in the benzyl group gives a soluble yellow compoundwith indigo white, while the dimethyl-phenyl-benzyl-ammonium chloridsulfonic acid, obtainable by combining dimethyl anilin sulfonic acidwith benzyl chlorid yields an insoluble yellow compound with indigowhite. New sulfonic acids and carboxylic acidsof organic ammoniumcompounds containing at least one aralkyl group suitable for useaccording to this invention are described in the application for LettersPatent-Serial No. 584,131, which describes the Production of organicammonium compounds such, for instance, as the anhydrid ofdimethyl-phenyl-benzyl-ammonium hydroxid disulfonic acid, either bydirect sulfonation, or by combining dimethyl-anilin, or the like withbenzyl-chlorid-sulfonic' acid or benzyl-chlorid-carboxylio acid.

The group capable of forming a salt, such as the sulfonic acid group orthe carboxylic acid group of the hydroxyl group, may either be presentas such, or anhydrid formation ma have taken place between the groupcapa le of forming a salt and another part of the compound, such forinstance, as occurs when the elements of hydrochloric acid split offfrom dimethyl-phenyl-benzylammonium chlorid-disulfonic acid. Under theterm group capable of forming a salt we include also such groups as SOCl,

which contain no hydrogen, and further the compound of the formula one:

which is formed by a lactone condensation frombenzalchlorid-ortho-sulfonic acid, can

- formaldehyde sulfoxylate, or hgdrosulfite in powder, in one hundredand fty parts of water, with seventy partsof dimetyl-phenyl-benZy'l-ammonium chlorid in one h11I1-' dred parts of water,and add five hundred and thirty parts of fifty per cent. gum thickening.

Example 2D2's0harging paste with zinc 0m'0Z.-Stir together one hundredparts of zinc oxid and one hundred parts of water, add seventy parts ofdimethyl-phe-i nyl-benzyl-ammonium chlorid in one hun dred parts ofwater, one hundred and fifty parts of sodium formaldehyde sulfoxylate;

or hydrosulfite, one hundred arts of sodium sulfite, forty parts of athirty per cent.

paste of anthraquinone, and three hundred and forty parts of a fifty percent. gum, thickening. In this example,-the zinc oxid I can be replacedby the corresponding quantity of other suitable metallic oxid, hydroxid,or salt.

After the material has been printed with Y a paste such as thosedescribed in the foregoing examples, it is steamed for about five-minutes in the continuous steamer, then treated with warm water towhich some caust1c soda ma have been added, then Washed, and fifia lysoaped. I

When either of th paste described in the foregoing examples is employeda s'desc ribed on material dyed'wi'th indigo, a new yellow insoluble.compound contaimng a leuco compound of indigo and the'benzyl residue isproduced, and thus yellow discharge effects are obtained which arestable against the action of washing and'soap. These yellow dischargeeffects are also stable against the action of an alkaline solution ofpotassium ferricyanid, thusdifiering from indigo, and

consequently if material obtained according to this example andcontaining a yellow discharge effect on a blue ground be treated with analkaline solution of potassium ferricyanid, the indigo is removed and ayellow pattern on a white ground is obtained.

Ewample Iii-Mix well together a paste of fifty arts of zinc white, fiftyparts of water, and ft-y partsof glycerin, fifty parts of a thirty er'cent. anthra uinone paste, fifty parts o dimethyl-pheny lbenzyl-ammonium chlorid' in fifty parts of water, fifty parts of sodium"formaldehyde sulfoxylate, five hundred and fifty parts of fifty percent.

British gum thickening, and fifty parts of dehydrodndigo bisulfite in'fifty parts of water. 7 p Print the paste on to white material, or onto material which has been dyed with-a dischargeable colo'rin azo dye,dry steam or from three to five minutes, and then wash. The brilliancyof the yellow discharge .efiect thus obtained can be increased bysubsequently assing the material through hot dilute alka i and thenthrough an acid bath. In the foregoing matter, suchas anexample 3, thequantities can be varied to 1 suit any particular case.

Example !,.-Prepare a paste from seventy parts of zinc oxid, seventyparts-of water, eighty parts of a thirty per cent.

' paste'of anthra uinone, a solution of one hundred parts 0benzyl-chlorid-para-sulfochlorid in one hundred parts of water, and onehundred parts of ammonium carbonate, and one hundred and twenty parts ofsodium formaldehyde sulfoxylate dissolved in threehundred and sixtyparts of a fifty per centgum thickening. Print this paste on to thematerial which hasbeen dyed with indigo, dry, steam forfive minutes insteam which is free from air, and pass'the material through a boilinghath containing five parts of thirty-five per cent. caustic sodasolution per thousand parts of Water, and finally wash the material.During the process of steaming the indigo is reduced to a leuco 1compound thereof which combines with sul- 'Iss fonated benzyl residue toform a stable yellow compound which is soluble in alkali. A whitedischarge effect is therefor obtained. A similar result is obtained ifthe benzylchlorid-para-sulfochlorid in the above example et be replacedby benzyl-chlorid-paracarboxylic acid or by the sodium salt ofbenzylchlorid-para-su1fonic acid.

Example 5.-Mix together one hundred parts of zinc oxid, made into apaste withone hundred parts of water, a solution of seventy parts of theammonium base produced from benzyl ehlorid anddimethylanilin-meta-sulfonic acid, in one hundred parts of water, addone hundred and fifty parts of sodium formaldehyde sulfoxylate orhydrosulfite, one hundred parts of sodium suliite, forty parts of athirty per cent. paste of anthraquinone, and three hundred and fortyparts of. a fifty per cent. gum

' thickening. This paste produces yellow disparts of sodium carbonateand eight hundred parts of water. Then print on to the material thuspadded a paste prepared from seventy parts of zinc oxid, seventy partsof glycerin, forty pafts of a thirty per cent. paste of anthraquinone,one hundred parts of sodium formaldehyde sulfoxylate, one hundred andfifteen parts of the inner anhydrid of dimethylhenyl-benzyl-ammoniumhydroxid disul onic acid, one hundred and fifty parts of Water, and fourhundred and fifty-five parts of an alkaline thickening (containing perone thousand parts four hundred parts of dextrin and six hundred partsof thirty-five per cent. caustic soda solution). Steam the material forfive minutes in the continuous steamer and pass through a bathcontaining ten cubic centimeters of waterglass per liter. During thesteaming, the coloring matter is reduced to a leuco compound thereofwhich combines with the snlfonated benzyl residue to form a solublestaple compound, which by the aftertreatment is washed away leaving awhite discharge effect. I

- Example 7.Prepare a paste from seventy parts of zine'oxid in seventyparts of water, seventy parts of the disulfonic acid prepared bysulfonating the ammonium base obtainable from dimethyl-anilin and benzylchlorid, one hundred parts of water, one hundred and fifty parts ofsodium formaldehyde sulfoxylate, one hundred parts of sodium sulfite,forty parts of a thirty per cent. paste of anthraquinone, and fourhundred parts of fifty per cent. gum thickening. Print this paste on tothe material which has been dyed with indigo, steam for fire minutes ina continuous steamer, pass it through a bath containing dilute causticsoda, during which process the soluble compound of leuco indigo with thesulfonatcd benzyl residue is dissolved away from the material andconsequently a white discharge effect is produced. Finally wash and, ifdesired, soap the material. In this example the disulfonie acidmentioned may be replaced, for instance, by the compound obtained bytreating with a sulfonating agent the condensation product of benzylchlorid with dimethyl-metanilic acid, or with dimethyl-amino-benzoicacid.

Example 8. Prepare a paste from one hundred parts of zinc oxid, onehundred parts of glycerin, eighty parts of the sodium salt ofbenzal-chlorid-meta-sulfonic acid (obtainable by treatingbenZaldehyde-metasulfonic acid with phosphorus pentachlorid and thensaponifying the benzal-chloridmeta-sulfochlorid thus obtained), onehundred parts of water, one hundred and fifty parts of sodiumformaldehyde sulfoxylate or hydrosulfite, forty parts of a thirty percent. paste or anthraquinone, and four hundred and thirty parts of afifty per cent. gum thickening. Print this paste on to the materialwhich has been dyed with indigo, steam for five minutes in steam whichis free from air, and then pass the material through a boiling bathcontaining five cubic centimeters of thirty-five per cent. caustic sodain each liter, and finally wash. The compound formed from the leucoindigo body and the benzyl derivative is soluble in dilute caustic soda,and consequently white discharge effects are obtained.

Example 9.-Prepare a paste from one hundred parts of zinc white, onehundred I parts of water, seventy parts of dimethyl-'benzyl-sulfinium-methyl-sulfate (obtainable by treatingmethyl-benzyl-sulfid with dimethyl sulfate) in one hundred parts ofwater, one hundred and fifty parts of sodium formaldehyde sulfoxylate orof hydrosulfite, one hundred parts of sodium sulfite, forty parts of athirty per cent. paste of anthraquinone, and three hundred and fortyparts of a fifty per cent. gum thickening. Print this paste on tomaterial which has been dyed with indigo, steam for five minutes in acontinuous steamer, wash with dilute caustic soda, and, if necessary,soap. In this way yellow discharge effects are obtained. 3

In this example 9, the sulfinium compound mentioned can be replaced byother suitable sulfininium compound, such for instance asdimethyl-benzyl-sulfininium chlorid (obtainable from dimethyl-sulfid andbenzylchlorid), which yields yellow effects on ma-" tcrial dyed withindigo; or dimethyl-benzy'lsulfinium-para-sulfonic acid which yieldssoluble compounds with leuco indigo and can therefore be employed forthe production of white discharge effects.

[:mmpl 10.Prepare a paste from seventy parts of zinc oxid, seventy partsof water, sixty parts of a thirty per cent. paste of anthraquinone,eighty parts of the ammonium salt obtainable frombenzyl-chl'oridpara-carboxylic acid and dimethyl-anilin, one hundredparts of water, one hundred and twenty parts of sodium formaldehydesulfoxylate, twenty-four parts of calcined soda, and four hundred andseventy-six parts of fifty per cent. gum thickening. Print this paste onto material which has been dyed with indigo, treat with steam which isfree from air, and then pass through a weakly alkaline bath. In this waywhite discharge effects are obtained. In this example 10, the ammoniumsalt aforesaid can be replaced by the di-ammonium salt obtainable frommeta-hydroxybenzyl-bromid carbonate (produced by brominat-ing cresylcarbonate at from one hundred and thirty to one hundred and sixtydegrees centigrade) and dimethyl-anilin.

Example 11.Prepare a paste from seventy parts of zinc oxid, seventyparts of glycerin, eighty parts of omegabrom beta methyl anthraquinone,eighty parts of sodium dimethyl-metanilate, one hundred parts of water,sixty parts of a. thirty per cent.. paste of anthraquinone, one hundredand twenty parts of sodium formaldehyde sulfoxylate and four hundred andtwenty parts of fifty per cent. gum thickening. Print this paste on tomaterial which has been dyed with indigo, steam in apparatus which isfree-from air, and then pass the material through a weakly alkalinebath, whereupon white discharge effects are obtained.

Example '12.-Prepare a paste from seventy parts of zinc oxid, seventyparts of glycerin,forty parts of a thirty per cent. paste ofanthraquinone, fifty parts of sodium dimethyl-metanilate, thirty partsof benzyl chlorid, one hundred and twenty parts of water, one hundredand forty parts of sodium formaldehyde sulfoxylate, and four hundred andeighty parts of fifty per cent. gum thickening. Allow this paste tostand for a few hours and then print it on to material which has beendyed with indigo, treat the material with steam which is free from air,and then wash it in a weakly alkaline bath. In this case the compoundwhich is produced from the leuco indigo and the benzyl residue is yellowand insoluble in alkali; consequently yellow discharge eifects areproduced.

In order to prepare one of our new compounds in the free state, stirtogether, in a vessel provided with a reflux apparatus, fifty parts ofindigo pure BASE, seventyfive parts of sodium formaldehyde sulfoxylate,seventy parts of zinc oxid, sixty-two parts of'dimethyl-phenyl-benzyl-ammonium chlorid, and one hundred and thirtyparts of Water, and gradually raise the temperature until the massboils, and maintain this temperature for about four hours. Then allowto'cool and, at a temperature of about seventy degrees centigrade, addtwo hundred and forty parts of alcohol. Stir till the mixture ishomogeneous, filter off the product and wash it with alcohol, and thenextract it with hot dilute alkaline hydrosulfite solution until anyunchanged indigo is removed. Then boil with dilute acetic acid, filter,wash and dry the product obtained. It consists of an orange coloredpowder which is insoluble in boiling dilute caustic soda solution, butwhich yields a blue-green solution in concentrated sulfuric acid, and onboiling with nitrobenzene gives a green solution, from which, oncooling, indigo separates out.

Now what we claim is 1. The process of producing new compounds bycombining an aralkyl residue with a leuco compound of a vat coloringmatter.

2. The process of producing a new compound by combining an aralkylresidue with a leuco compound of a vat coloring matter in the presenceof fibrous material.

3. The process of producing new compounds on fiber by applying to thefiber a vat coloring matter and a suitable aralkyl compound and causingthe vat coloring matter to be reduced to its leuco compound and tocombine with the aralkyl compound substantially as hereinbeforedescribed.

4. The process of producing a new compound by combining a benzyl residuewith a leuco compound of a vat coloring matter.

5. The process of producing a new compound by combining an aralkylresidue with a leuco compound of an indigo coloring matter. 1

6. The process of producing a new compound by combining'an aralkylresidue with a leuco compound of an indigo coloring matter in thepresence of fibrous material.

7. The process of producing new compounds on fiber by applying to thefiber an indigo coloring matter and a suitable aralkyl compound andcausing the indigo coloring matter to be reduced to its leuco compoundand to combine with the aralkyl compound 1 substantially as hereinbeforedescribed.

agent, substantially as hereinbefore described.

10. The process of producing new compounds by treating fiber, which hasbeen dyed with an indigo coloring matter, with a reducing agent and:with an aralkyl compound in which the aralkyl residue contains a groupcapable of forming a salt, thus causing the leuco coloring matter to beproduced and to combine with the aralkyl residue sub stantially ashereinbefore described.

11. The process of producing new com pounds from fiber which has beendyed with an indigo coloring matter, by causin the indigo coloringmatter to be reduce to its leuco compound and to combine with asulfonated benzyl residue.

12. The process of producin new compounds by applying to fiber which hasbeen dyed with indigo coloring matter, a paste containing formaldehydesulfoxylate and an inner anhydrid of adimethyl-phenyl-benzyl-ammonium-hydroxid sulfonic acid in which thebenzyl residue contains at least one sulfonic acid residue, thensteaming the material and thereby causing the indigo coloring matter tobe reduced and to combine with the sulfonated benzyl residue.

13. The process of producing new compounds by applying to fiber whlchhas been dyed with indigo coloring amtter, a paste containingformaldehyde sulfoxylate and the inner anhydrid ofdimethyl-phonyl-benzyl-ammonium-hydroxid disulfonic acid, ob-

tainable by sulfonating dimethyl-phenylbenzyl-ammonium chlorid, thensteaming the material and thereby causing the indigo coloring matter tobe reduced and to combine with the sulfonated benzyl residue.

14:. As new articles of manufacture compounds containing an ara-lkylresidue combined with a leuco compound of a vat coloring matter, whichcompounds are stable in the presence of alkali and of air, not be ingconverted into the corresponding vat coloring matters by such treatment.

.15. As new articles of manufacture compounds containing an aralkylresidue combined with a leuco compound of an indigo coloring matter,which new compounds possess yellow to red to brown shades and are stablein the presence of alkali and of air and which are soluble in dilutealkali when the aralkyl residue contains a group capable of forming asalt but are otherwise insoluble.

16. As new articles of manufacture compounds containing a benzyl residuecombined with a leuco compound of an indigo coloring matter, which newcompounds possess yellow to red to brown shades,'are stable in thepresence of alkali and of air and are soluble in dilute alkali when thebenzyl residue contains a group capable of forming a salt, but areotherwise insoluble.

17. As new articles of manufacture compounds containing a sulfonatedbenzyl residue combined with a leuco compound of an indigo coloringmatter, which new compounds possess yellow to red to brown shades, arestable in the presence of alkali and of air, and are soluble in dilutealkali.

18. As new articles of manufacture comounds containing a benzylresiduecom- Eined with a leuco compound of an indigo coloring matter and ametallic compound, which new compounds possess yellow to red to brownshades, are stable in the presence of alkali and of air and are solublein dilute alkali when the benzyl residue contains a group capable offorming a salt, but are otherwise insoluble.

19. As new articles of manufacture compounds containing a sulfonatedbenzyl residue combined Wllih' a leuco compound of an indigo coloringmatter and a metallic compound, which new compounds possess yellow tored to brown shades, are stable in the presence of alkali and of air,and are soluble in dilute alkali.

20. As new articles of manufacture compounds containing a sulfonatedbenzyl residue combined with indigo white and zinc oxid, which newcompounds possess an orange color, are stable in the presence of alkaliand air, and are soluble in dilute alkali.

In testimony whereof we have hereunto set our hands in the presence oftwo subscribing witnesses.

KARL REINKJNG. ARMAND JULIUS STIEGELMANN.

\Vitnesses:

J. ALEX. LLOYD, J OSEF TSCIFFER.

